Hermetically Sealed Wet Electrolytic Capacitor

Active Publication Date: 2012-05-03
KYOCERA AVX COMPONENTS CORP
View PDF5 Cites 12 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0005]Other features and aspects of the presen

Problems solved by technology

Unfortunately, such wet capacitors can experience problems when the liquid electrolyte leaks.
This may cause leaks to occur around conventional non-hermetic polymeric seals, where terminal wires protrude from the capacitor casing.
Still, the hermetic seal itself can sometimes become corroded by the liqu

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Hermetically Sealed Wet Electrolytic Capacitor
  • Hermetically Sealed Wet Electrolytic Capacitor
  • Hermetically Sealed Wet Electrolytic Capacitor

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0068]A wet electrolytic capacitor was formed in accordance with the present invention. A liquid seal was initially formed in the manner shown in FIGS. 7-8. More particularly, a glass-to-metal seal 300a was threaded onto a wire 320 through a tantalum tube 322, with the top of the tube resting against a bead 380 at the end of the wire. A first perform 350a containing a PFA layer 360 and a PTFE layer 362 (obtained from Electrolock) was then positioned over the wire 320 and on the seal 300, with the PFA layer 360 against the seal 300a. Another preform 350b was also placed on the wire 320 such that the PTFA layers of each preform mated together. A second glass-metal seal 300b was threaded onto the wire 320, upside down relative to the first. Additional pairs were positioned in the same way until a manageable stack was obtained. A weight 370 (25-50 grams) was attached to the wire 320, and the entire assembly was then placed in an oven using a fork-like support 373 on the bottom of the st...

example 2

[0070]A wet electrolytic capacitor was formed in accordance with the present invention. A liquid seal was initially formed in the manner shown in FIGS. 9-10. More particularly, a glass-to-metal seal 400 was threaded onto a wire through a tantalum tube. A preform 450 containing a PFA layer 460, PTFE layer 462, and PFA layer 464 (obtained from Electrolock) was then positioned over the wire 420 and on the seal 400, with the PFA layer 460 against the seal 400. A weight 470 (10 grams) was attached to the wire 420, and the entire assembly was then placed in an oven. The oven was raised to 330° C. and held for a period of 15 to 30 minutes, at which time the oven is turned off. When cooled, the stack was removed and disassembled such that the individual seals were accessible and contained a fluorocarbon disk laminated to the tantalum-glass-metal portion. The resulting seal was then assembled with a tantalum anode 480, metal casing (not shown), and electrolyte in the manner described in Exam...

example 3

[0071]A wet electrolytic capacitor was formed in accordance with the present invention. As shown in FIG. 11, a disk of a single PFA layer 550 was threaded onto a formed anode riser wire 542, and then the anode riser wire was inserted into the tube 556. The seal 500, disk 550, and anode 580 were then placed in an oven at 333° C. upside down, so the weight of the anode compressed the PFA disk. The assembly was held at temperature for ½ hour, and then cooled. The assembly was then placed into a metal case 512, into which an amount of electrolyte had been introduced, and a Teflon support 555 had been placed. The seal was pressed into the can, and the circumference welded. The center tube was sealed with a laser, and the leads attached in the manner known to the art.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

A wet electrolytic capacitor that contains a hermetically sealed lid assembly is disclosed. More specifically, the lid assembly contains a lid (e.g., titanium) that defines an internal orifice. A conductive tube may extend through the orifice that is of a size and shape sufficient to accommodate an anode lead. An insulative material is also provided within the orifice to form a hermetic seal (e.g., glass-to-metal seal), such as between the conductive tube and the lid. The lid assembly also includes a liquid seal that is formed from a sealant material. The liquid seal coats a substantial portion of the lower surface of the lid and hermetic seal to limit contact with any electrolyte that may leak from the casing. To help achieve such surface coverage, the sealant material is generally flowable so that it can be heated during production of the capacitor and flow into small crevices that would otherwise remains uncoated.

Description

BACKGROUND OF THE INVENTION[0001]Electrolytic capacitors typically have a larger capacitance per unit volume than certain other types of capacitors, making them valuable in relatively high-current and low-frequency electrical circuits. One type of capacitor that has been developed is a “wet” electrolytic capacitor that includes a sintered tantalum powder anode. These tantalum “slugs” have very large internal surface area. These tantalum slugs first undergo an electrochemical oxidation that forms an oxide layer coating acting as dielectric over the entire external and internal surfaces of the tantalum body. The anodized tantalum slugs are then sealed in cans containing a highly conductive and generally corrosive liquid electrolyte solution, having high surface area with conductive linings allowing the flow of the current to the liquid electrolyte solution. Unfortunately, such wet capacitors can experience problems when the liquid electrolyte leaks. For example, gases (e.g., hydrogen)...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): H01G9/10
CPCH01G9/08H01G9/10H01G9/145H01G9/0425H01G9/06
Inventor MILLMAN, WILLIAM A.JACKSON, EDBATES, JAMES STEVENGALVAGNI, JOHN
Owner KYOCERA AVX COMPONENTS CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap